How to solve ‘Can’t locate DBD/mysql.pm’
As simple as:
yum install perl-DBD-mysql
14
Jan
Category Archives: linux
08
Jul
Monitoring Galera cluster using Percona Nagios plugins on Debian
1. Download the repository packages:
wget https://repo.percona.com/apt/percona-release_0.1-3.$(lsb_release -sc)_all.deb
2. Install it:
dpkg -i percona-release_0.1-3.$(lsb_release -sc)_all.deb
3. Update the packages list:
apt-get update
4. Install
apt-get install percona-nagios-plugins
5. Grant the privileges:
GRANT USAGE, SELECT, REPLICATION CLIENT on *.* to 'test'@'localhost' IDENTIFIED BY 'password';
6. Test:
/usr/lib64/nagios/plugins/pmp-check-mysql-status -x wsrep_cluster_status -C == -T str -c non-Primary -l test -p password
17
Jun
How to test CORS using curl
curl -H "Origin: https://www.pydelion.com" \ https://static.pydelion.com/style/all.css -I -v
09
Jun
Linux: add swap file – onliner
fallocate -l 512M /mnt/swap ; \ dd if=/dev/zero of=/mnt/swap bs=512 count=1048576 \ ; mkswap /mnt/swap ; swapon /mnt/swap ; swapon -s ; free -m
03
Jun
ansible: ‘Sending passwords in plain text without SSL/TLS is extremely insecure’
ansible MySQL replication fails to change master with the following error: ‘Sending passwords in plain text without SSL/TLS is extremely insecure.’
To fix the problem open /usr/lib64/python2.6/site-packages/MySQLdb/cursors.py and change:
defer_warnings = False
to
defer_warnings = True
This is ugly but it works.
12
May
Postfix warning: database /etc/postfix/virtual.db is older than source file /etc/postfix/virtual
Fire:
postmap /etc/postfix/virtual
Once done :
service restart postfix
That’s it.
28
Apr
rpm: show packages with names only
Sometimes it’s needed to get only packages names only using rpm. This is how it can be done:
rpm -qa --qf "%{NAME}\n"
11
Apr
sed: replacing multiple empty lines with one
As simple as:
sed -e '/^$/N;/^\n$/D' <file>
25
Mar
OpenSSL: How to check if a certificate matches a private key
openssl x509 -noout -modulus -in example.crt | openssl md5 openssl rsa -noout -modulus -in example.key | openssl md5
Should be equal.
21
Jan
How to get and debug WordPress SQL queries
WordPress provides handy way to get all queries and to debug them easily.
To enable queries collecting add the following in your wp-config.php:
define('SAVEQUERIES', true);
Next should be added to your theme footer (wp-content/themes/<your_theme>/footer.php)
<?php echo get_num_queries(); ?> queries in <?php timer_stop(1); ?> seconds.
<?php
if (current_user_can('administrator')){
global $wpdb;
echo "<pre>";
print_r($wpdb->queries);
echo "</pre>";
}
?>
At the end you should be able to get something like:
134 queries in 0.301 seconds.
and a bunch of SQL queries.